Motion-compelling mechanism for a hand tool incorporating stop means



July 26, 1966 a. J. FlLlA 3,262,342

MOTION-COMPELLING MECHANISM FOR A HAND TOOL INCORPORATING STOP MEANS Filed July 31, 1964 INVENTOR Geovqe J. FHio.

RM Ma Deiio' ATTORNEYS 3,262,342 MOTION-COMPELLING MECHANISM FOR A HAND TOOL INCORPORATING STOP MEANS George J. Filia, Shelton, Conm, assignor to Sargent & Company, New Haven, Conn.

Filed July 31, 1964, Ser. No. 386,594 4 Claims. (Cl. 81-313) This invention relates to hand tools and more particularly relates to hand tools having a motion compelling mechanism which compells a predetermined minimal motion of the work engaging portions of the hand tool once closure of the work-engaging members has been initiated.

In hand tools, for example, those of the plier type such as might be used for crimping a ferrule into an uninsulated end of wire to thereby provide a mechanical and electrical connection, it is desirable to provide a tool with a mechanism which predetermines the minimum closure of the work-engaging parts, such as jaws, to prevent the jaws from being opened before the ferrule has been crimped the required amount. In a plier type hand tool such a mechanism may comprise a ratchet carried on one handle thereof and a pawl carried on the other handle thereof and so arranged that once the ratchet and pawl are engaged, the pawl must traverse the ratchet before the handles, and therefore the jaws, may be opened.

While such an arrangement insures that a minimum crimping pressure is exerted on the ferrule it does not limit the crimping pressure which may be exerted thereon. Therefore, it has been the practice in some hand tools provided with a motion compelling mechanism to provide a limit stop on the handles or on the jaws actuated thereby which limit the closure of the jaws upon completion of the compelled motion.

In crimping a ferrule, the depth of crimp is critical to obtain the proper mechanical and electrical connection of the ferrule to a conductor, and a non-adjustable ratchet and pawl do not allow for manufacturing tolerances which can cause the depth of crimp to vary from tool to tool. Therefore, such crimping tools have been provided with means for adjusting the amount of compelled motion to provide flexibility in the tool. However, these known tools provide no satisfactory way of changing the stop for the jaws when the magnitude of the compelled motion is adjusted.

Accordingly, the present invention provides a hand tool having a new and improved motion-compelling mechanism-jaw limiting stop which predetermines both the minimum and maximum crimping pressure exerted on a workpiece and thereby sets a range of crimping pressures.

An object of this invention is to provide a hand tool having new and improved motion-compelling mechanism and jaw stops which coact to predetermine the range of crimping pressure which the hand tool may exert on a workpiece.

Another object of this invention is to provide a hand tool having a new and improved cooperating motioncompelling and limit-stop arrangement wherein adjustment of the magnitude of the compelled motion automatically adjusts the limit stop and thereby predetermines the range of pressures which the hand tool may exert on a workpiece. I

A further object of the invention is to provide a hand tool having a new and improved motion-compelling mechanism and limit-stop arrangement wherein the motion-compelling mechanism also provides the limit stop and adjustment of the minimal compelled motion also provides a desired change in the maximum motion of the aws.

The features of the invention which are believed to be novel are pointed out with particularity and distinctly claimed in the concluding portion of the specification.

United States Patent 3,262,342 Patented July 26, 1966 "ice The invention, however, both as to its organization and operation together with further objects and advantages thereof may best be appreciated by reference to the several figures of the drawing in which:

FIG. 1 is a side elevational view, partly in section, of a hand tool constructed in accordance with the invention, with the handles in a closed position;

FIG. 2 is a similar view of the tool of FIG. 1 with the handles in an open position, and the handles broken off;

FIG. 3 is a sectional view taken along line 33 of FIG. 1;

FIG. 4 is a sectional view taken along line 44 of FIG. 1;

FIG. 5 is a view similar to FIG. 3 showing a modification of the tool of FIG. 1;

FIG. 6 is an enlarged diagrammatic view of a motioncompelling mechanism and limit stop utilized in the structure of FIG. 5; and

FIG. 7 is a view of a ratchet and limit stop-providing member which may be utilized in the invention, and more specifically in the tool of FIG. 1.

A hand tool which embodies the invention is generally indicated by the reference numeral 10 and comprises a pair of handles 11 and 12 of generally U-shape crosssection, pivotally mounted together by a pin 13. The handles 11 and 12 are biased toward an open position by a spring 14 about pivot pin 13 and having arms 15 and 16 bearing upon handle members 11 and 12. Pivotally mounted to each of handles 11 and 12 by pins 17 and 18 are jaws 19 and 20, respectively, defining crimping dies 21 therein. Each of jaws 19 and 20 is pivotally connected on either side thereof to a pair of strap members 22 (only one shown) on either side thereof by pivot pins 23 and 24, respectively. Disposed between jaws 19 and 20 in a recess provided therefor is a member such as a pin 25 about which the jaws lock or rotate to provide smooth movement thereof.

The tool as thus far described comprises the well-known toggle action type crimping pliers and is well known to those skilled in the art. This particular form of hand tool is shown for purposes of illustration only, and the invention, hereinafter exemplied, may be embodied in various types of hand tools.

A lever member 27 providing ratchet teeth 28 along one end thereof is pivotally mounted at the other end thereof about pin 13. Lever 27 is also mounted to bandle 12 as more clearly shown in FIG. 4. Lever 27 is provided with an aperture 29 therethrough which receives therein and adjustment member in the form of a bolt 30 having a threaded portion 31 extending through the other side of handle member 12 and having a nut 32 threadably received thereon. Bolt 30 has a round head 33, and a circular shoulder portion 34 adjacent the round head is positioned in a circular aperture 35 in handle 12. Shaft portion 36 of bolt 30 is eccentric with respect to the head 33 of bolt 30. When bolt 30 is rotated shaft 36 revolves about the axis A of bolt 30 and engages the edges-defining aperture 29 to pivotally move lever 27 about pin 13 and adjust the relative position of lever 27 and handle 12.

The ratchet teeth 28 on lever 27 are arranged to be engaged by a pawl 37 pivotally mounted on handle 11 by means of a pin 38. A spring 39 is attached between pawl 37 and a pin 40 carried by handle 11 to yieldably maintain pawl 37 in a position to cooperate with ratchet 28. The pawl and ratchet provide a motion-compelling mechanism.

As the handles 11 and 12 are closed from the position shown in FIG. 2, pawl 37 engages the teeth of ratchet 28 thereby tending to rotate pawl 37 in a clockwise direction. As the handles are closed further the pawl will progres- 3 sivelycontact each of the teeth in ratchet 28. However, once pawl 37 engages the ratchet teeth the pawl cannot thereafter be rotated in a reverse direction to permit the handle to be opened until the pawl clears the ratchet as shown in FIG. 1. The bolt 30 provides a positive means of adjusting the relative position of lever 27 on handle 12 to set the minimal jaw closure of the tool and thereby accurately determines the minimal motion of the jaws when the handles are closed. This particular arrangement is described in more detail and claimed in the co-pending application of George I. Filia, Serial No. 166,856 filed January 17, 1962, now Patent No. 3,157,075, assigned to the same assignee as the present invention.

In accordance with the invention, the pawl and ratchet assembly is so constructed that in addition to providing a motion-compelling mechanism which predetermines the minimal closure of the jaws, the motion-compelling mechanism further cooperates to limit jaw closure and thereby determine the maximum closure of the jaws.

As shown in FIGS. 14, an abutment member 42 is nonrotatably pinned or otherwise secured to lever 27 at 43 and is in fixed relation therewith. Member 42 is provided with an extending =ledge or stop 44 which protrudes transversely of the line of the ratchet teeth and the path of travel of pawl 37, and is constructed and arranged to be engaged by pawl 37 after pawl 37 clears ratchet 28, as more clearly seen in FIG. 1.

Member 42 is provided with an aperture 46 similar to aperture 29 in lever 27 and coinciding therewith so that adjustment of lever 27 through bolt 30 also adjusts the position of member 42. With this arrangement once pawl 37 has engaged one of the teeth of ratchet 28 the handles cannot be opened until pawl 37 traverses all of the ratchet teeth. This predetermines the minimal closure of jaws 19 and 20. Now, as pawl 37 travels past ratchet 28 to the position shown in FIG. 1, pawl 37 will engage abutment ledge 44 and stop or limit further closure of the handles and, therefore, jaws 19 and 20.

FIGS. and 6 illustrate an alternate embodiment wherein the abutment-providing member may be adjusted relativ to the ratchet-providing member. In FIGS. 5 and 6 similar reference numerals are used, with respect to FIGS. 1-4, to identify similar parts. The abutment member 42 is made adjustable with respect to lever 27 and ratchet 28 by means of a shaft 47 threadably received in lever member 27 and having a pin-like portion 48 eccentric thereto extending into an elongated aperture 49, similar to aperture 29, defined in member 42. Thus as member 47 is rotated portion 48 thereof will engage the walls-defining aperture 49 and pivotally move member 42 about bolt 30 as indicated by the arrows B, FIG. 6. At the same time both lever member 27 and member 42 may b simultaneously adjusted with respect to pawl 37 by adjustment bolt 30 in the direction of the arrows C, as previously explained.

With this arrangement the relative position of pawl 37 and ratchet 28 may be adjusted by means of bolt 30 which simultaneously adjusts abutment member 42. Alternately, the position of abutment ledge 44 may be independently adjusted by means of threaded shaft 47.

In FIG. 7 lever 27 with ratchet teeth 28 thereon is provided with an extending abutment ledge 44a adapted to be engaged by the pawl 37 and to predetermine the maximum closure of jaws 19 and 20. It will be noted that the structure of FIG. 7 in essence combines the lever 27 and member 42 of FIGS. 1-4 into one integral platelike member.

It may thus be seen that the objects of the invention set forth as Well as those made apparent from the foregoing description are efficiently attained. While a preferred embodiment of the invention has been set forth for purposes of disclosure, modifications to the disclosed embodiment of the invention as well as other embodiments thereof may occur to those skilled in the art. Accordingly, the appended claims are intended to cover all modifications and embodiments of the invention which do not depart from the spirit and scope thereof.

What is claimed is:

1. In a tool of the type having first and second handles relatively swingable :on a common pivotal axis and operatively connected to first and second jaws respectively for relative opening and closing movement of the jaws on corresponding movement of the handles, the combination comprising a first member providing a ratchet segment movable only bodily with the first handle in its swinging movements during the operation of the jaws and supported from the first handle, a second toothed member on an axis parallel to and spaced from the pivotal axis of the handles for engagement with the teeth of the ratchet segment and carried by the second handle and angularly movable with reference thereto against a spring bias, the second toothed member being swingable on the axis of said handles beyond said ratchet segment in both directions, the bias of the second toothed member being eifective to yieldably maintain said last-mentioned member in position to engage the ratchet teeth as the handes are relatively closed upon each other and opened so that after traversing one ratchet tooth reverse movement of the handles is prevented until the second toothed member has traversed every one of the ratchet teeth, and said second member being spring biased toward a neutral position and having ca-m means thereon coacting with means on said first member to angularly deflect the second toothed member in either direction from its neutral position in accordance with the direction of movement of the handles, and means on said first member providing an abutment positioned transversely of the path of travel of said second toothed member for engagement by the latter on relative closing movement to limit further movement of said second toothed member after the latter has moved a predetermined distance beyond the ratchet teeth so that further closure of the handles is prevented.

2. A tool as defined in claim 1 wherein said ratchet segment is formed by teeth on an edge portion of a plate providing said first member and said means on said first member providing an abutment is formed by another edge portion, and wherein said plate is mounted for angular movement with reference to the first handle, and means is provided on the last-mentioned handle to adjust said plate angularly to vary the travel of said ratchet teeth and said abutment.

3. A tool as defined in claim 1 wherein said ratchet segment is formed on an edge portion of a plate mounted for angular movement with reference to the first handle, said means on said first member providing an abutment being formed by an edge portion of a second plate for angular movement in superimposed relation to the first plate, and wherein means is provided on the lastmentioned handle extending through both plates to adjust them angularly to vary the travel of the ratchet teeth and said abutment.

4. A tool as defined in claim 3 wherein said first and second plates are provided with means extending through both plates to adjust said ratchet teeth relatively to said abutment.

References Cited by the Examiner UNITED STATES PATENTS 2,933,000 4/1960 Wood 81-3 13 X 3,157,075 11/1964 Filia 81-313 FOREIGN PATENTS 1,342,312 9/1963 France.

1,089,834 9/ 1960 Germany.

WILLIAM FELDMAN, Primary Examiner.

MILTON S. MEHR, Assistant Examiner. 

1. IN A TOOL OF THE TYPE HAVING FIRST AND SECOND HANDLES RELATIVELY SWINGABLE ON A COMMON PIVOTAL AXIS AND OPERATIVELY CONNECTED TO FIRST AND SECOND JAWS RESPECTIVELY FOR RELATIVE OPENING AND CLOSING MOVEMENT OF THE JAWS ON CORRESPONDING MOVEMENT OF THE HANDLES, THE COMBINATION COMPRISING A FIRST MEMBER PROVIDING A RATCHET SEGMENT MOVABLY ONLY BODILY WITH THE FIRST HANDLE IN ITS SWINGING MOVEMENTS DURING THE OPERATION OF THE JAWS AND SUPPORTED FROM THE FIRST HANDLE, A SECOND TOOTHED MEMBER ON AN AXIS PARALLEL TO AND SPACED FROM THE PIVOTAL AXIS OF THE HANDLES FOR ENGAGEMENT WITH THE TEETH OF THE RATCHET SEGMENT AND CARRIED BY THE SECOND HANDLE AND ANGULARLY MOVABLE WITH REFERENCE THERETO AGAINST A SPRING BIAS, THE SECOND TOOTHED MEMBER BEING SWINGABLE ON THE AXIS OF SAID HANDLES BEYOND SAID RATCHET SEGMENT IN BOTH DIRECTIONS, THE BIAS OF THE SECOND TOOTHED MEMBER BEING EFFECTIVE TO YIELDABLY MAINTAIN SAID LAST-MENTIONED MEMBER IN POSITION TO ENGAGE THE RATCHET TEETH AS THE HANDLES ARE RELATIVELY CLOSED UPON EACH OTHER AND OPENED SO THAT AFTER TRAVERSING ONE RATCHET TOOTH REVERSE MOVEMENT OF THE HANDLES IS PREVENTED UNTIL THE SECOND TOOTHED MEMBER HAS TRAVERSED EVERY ONE OF THE RATCHET TEETH, AND SAID SECOND MEMBER BEING SPRING BIASED TOWARD A NEUTRAL POSITION AND HAVING CAM MEANS THEREON COACTING WITH MEANS ON SAID FIRST MEMBER TO ANGULARLY DEFLECT THE SECOND TOOTHED MEMBER IN EITHER DIRECTION FROM ITS NEUTRAL POSITION IN ACCORDANCE WITH THE DIRECTION OF MOVEMENT OF THE HANDLES, AND MEANS ON SAID FIRST MEMBER PROVIDING AN ABUTMENT POSITIONED TRANSVERSELY OF THE PATH OF TRAVEL OF SAID SECOND TOOTHED MEMBER FOR ENGAGEMENT BY THE LATTER ON RELATIVE CLOSING MOVEMENT TO LIMIT FURTHER MOVEMENT OF SAID SECOND TOOTHED MEMBER AFTER THE LATTER HAS MOVED A PREDETERMINED DISTANCE BEYOND THE RATCHET TEETH SO THAT FURTHER CLOSURE OF THE HANDLES IS PREVENTED. 